GoldenRod 45 A+ antenna

[Marconi]

I was just trying to show the differences that I've notice checking this unique antenna out over the years. Much of the details of the past are now gone. I just got lucky to find anything older on the Internet and on the forum that is also old.

I'm not making any claims, I just remember I saw a good match with lots of bandwidth, and in my simple way I figured the old stories about an expanded BW meaning less gain to a point. Not my rule...just an opinion.

I understand everything you said here Mr. Slowmover.

 

[jessejamesdallas]

I seen that video before I ordered mine, so when I received mine, first thing I did was spread the loops like in the video to lower the SWR...However, instead of going down, mine went up...I then noticed narrowing the loops made a difference, but not enough...

Next I just angled the loops down (which it looks like what is pictured in the instructions) and that did lower the SWR...guess when all else fails...read the instructions.

Was thinking maybe the loops needed to be shortened some, but didn't really want to go cutting and not knowing for sure.

 

[Marconi]

Was thinking maybe the loops needed to be shortened some, but didn't really want to go cutting and not knowing for sure.

Jesse, it has been a long time since I worked my GR45, but I recall the square bracket that supported and connected the Top Hat wires could be made a bit longer or shorter. I did get a good match, but the details are probably all buried in my old Antenna Notes somewhere.

The Top Hat on my old SP500 models was just such a tool to used to help adjust the match...go slanting up and/or go slanting down with those 9" x 1/8" would make a difference in the match to some degree.

The AstroPlan Top Hat adjustment have a similar effect as best I can recall.

 

[Marconi]

Here is my most recent GR45 over Real Earth and in Free Space, with a Starduster type ground plane below.

Lee is the WWDX.com member, Dr_DX on this forum. He provided me his dimensions for my old GR45 I sold him some months ago. Lee has all of my old antenna stuff and plenty of antennas, and odds and ends. If you want something in that inventory I'm sure he will give your requests due considerations, but he is not going to give it away.....

1. Real Earth with coil matched and tuned. I used a conventional Top Hat for convenience to avoid making curved elements.

2. Free Space model same as #1, showing the Average Gain Results = 1.

With Eznec this AG value suggest that the model is effectively good for consideration as to accuracy. 1 being perfect.

Just in case you guys are confused...I consider modeling a tool and needing verification in Real World testing in order to suggest truth of accuracy.

Here are the GR45 specs. https://www.lightningantennas.com/mobile

 

[Slowmover]

I seen that video before I ordered mine, so when I received mine, first thing I did was spread the loops like in the video to lower the SWR...However, instead of going down, mine went up...I then noticed narrowing the loops made a difference, but not enough...

Next I just angled the loops down (which it looks like what is pictured in the instructions) and that did lower the SWR...guess when all else fails...read the instructions.

Was thinking maybe the loops needed to be shortened some, but didn't really want to go cutting and not knowing for sure.

I left the top hat “flat plane” (as said), as having only an SWR Bridge versus use of an Antenna Analyzer, I could detect no difference.

I wouldn’t mean to say or imply I’m correct about changing or not changing top hat configuration. My “adjustments” (tuning) is nothing past what I received. (The only point). What I wrote above was — as it were — historical.

I’m very much looking forward to what JJD finds.

.

 

[Marconi]

Me too.

 

[jessejamesdallas]

With the MFJ analyzer (259b) just putting the GR45 together, with the top hat loops flat out to the sides, with no adjustments, SWR was at 1.5 across from channel 1 to 40...

OK, not bad, I think that was what Lightning stated the antenna to be at.

But, X=4 to X=9 too and Ohm was 59 to 60...

Bending the loops out just a bit made things worse, but I did notice on the MFJ the lower band channels below 11 meter was almost flat on the analyzer.

So, bent the loops back to where they were originally, then started tilting them down (making them look droopy) then I seen SWR get to where I was expecting to see it, and the more I angled the loops down, the better my readings got.

So, bent down to where the loops almost touch the coil, SWR is at 1.0 across all 40 channels, Ohm is at 51 - 52, X=0 across all channels, match efficiency was at 99%...

So either this is the best tuned mobile antenna I have ever had, or it's one expencive dummy load...

It does get out at least 15 air miles from downtown Dallas over to the east side of Mesquite, I did make a contact Friday with one of my buddys with it, but then again his Base set-up is pretty good, I could probably make a contact with him from Oklahoma using a wire coat hanger...so, may need to do a little more "on air" comparison checks.

 

[Marconi]

Jessie, I don't recall tuning the TopHat anyway but flat, but I did find on occasion, one of the wires had slipped down like you describe, beside the coil more or less. I just moved it up and re-tightened it back down.
I thought the TopHat bracket was weak.

I had a tree near the static installation on a 25' PushUP pole and I figured the wind and/or a limb must have hit the wire.

I never mounted mine on a mobile.

I found the antenna responsive at that height and compared it to a 102" whip replacing the GR45. The whip always seemed to produce a slight but detectable difference in the signals.

In those days I was buying the manufacture's claim that the GR45 was responsive to horizontal polarity signals, but in comparing I saw no such response compared to the whip. I just wished I had put the GR45 up on my 50' foot pushup and checked it out.

IMO, it is hard to be a whip even among the high gain coil type designs that I've used.

 

[jessejamesdallas]

The Top Hat bracket is weak....Nothing IMO on this antenna looks like it was meant to fly down the road at 80mph on the top of a vehicle...

The shaft is sorta flimsy looking, fairly small diameter compared to other aluminum antennas with shafts the same length...But I didn't notice that being a problem, it seems to ride just fine at highway speeds.

The coil itself I thought could have been attached better, Just thinking over a long period of time on a mobile, some of these small screws they used putting it together, might wiggle loose.

IMO it looks like it would make a better small base antenna, than a mobile...But I'm going to give it a week or so to see what it will do.

 

[Marconi]

Good Idea Jesse.

I would try and get it up 36' or more. It may shine with a little height to fly at. Give some consideration for how quiet it compares to others you may have up and working.

With the large BW it is a bit lossy, as noted by the mildly lower gain signals I saw compared to my 102" whip, and it could possibly hear crickets too...just like my Starduster.

 

[Marconi]

Jesse, have we ever made contact back in the days during contests?

 

[jessejamesdallas]

Jesse, have we ever made contact back in the days during contests?

maybe...can't remember that far back to tell ya the truth...I've slept since then

 

[Marconi]

I do have a note that I talked with a member name Dealer up in that area around Dallas and Ft. Worth during the old Contests days...maybe he was a bit West of FW. Did you know him?

Just checked my old DX contest roster and those contacts were in 2003, you didn't show up according to your profile until 2005.

 

[jessejamesdallas]

"Dealer" doesn't ring a bell...but if he was west of Fort Worth thats probably why...West Ft.Worth too far from me for local talk, specially with all the ground clutter in between...If he were east of me, that would be a different story, I have better ears east since there's less electrical interference.

 

[Marconi]

I grew up as a kid in Mansfield till the 4th grade.